1. Field of the Invention
The present invention relates to harvesting or crop treating equipment, and more particularly to cotton strippers of the type in which a plurality of stripping fingers are mounted in parallel, spaced-apart relation and are driven through cotton plants to strip the cotton bolls from the plants.
2. History of the Prior Art
The prior art contains various examples of arrangements for adjusting the height of and otherwise positioning crop harvesting apparatus. For example, in U.S. Pat. No. 3,714,767, Hubbard et al, CROP HARVESTER, issued Feb. 6, 1973 and assigned to the assignee of this application, a pair of harvesting units are individually adjusted for height. Each unit employs a system using a sensor in combination with a valve, a supply of pressurized fluid and a cylinder which responds to the pressurized fluid as controlled by the valve to adjust the height of the associated unit.
U.S. Pat. No. 3,714,767 is typical of crop harvesting equipment of the type in which one or more cylindrical structures rotatable about vertical axes are employed to perform the harvesting. Other examples include U.S. Pat. No. 3,359,712, Hubbard, COTTON PICKER, issued Dec. 26, 1967, U.S. Pat. No. 3,369,352, Hubbard, COTTON PICKER, issued Feb. 20, 1968, U.S. Pat. No. 3,373,547, Hubbard, COTTON PICKER, issued Mar. 19, 1968 and U.S. Pat. No. 3,427,791, Hubbard, METHOD AND APPARATUS FOR POSITIONING DOFFING STRUCTURE IN A COTTON PICKER, issued Feb. 18, 1969, each of the Hubbard patents being assigned to the assignee of this application.
A different height sensing and adjusting arrangement is shown in U.S. Pat. No. 3,643,407, Hubbard et al, AUTOMATIC HEIGHT ADJUSTMENT OF CROP HARVESTER, issued Feb. 22, 1972 and assigned to the assignee of this application. In Pat. No. 3,643,407 two different systems are used in conjunction with two different cylinders, the first cylinder providing basic height positioning and the second cylinder providing minor adjustment of the height.
Other types of crop harvesting equipment for use with crops such as cotton employ a plurality of parallel, spaced-apart fingers for stripping the cotton bolls from the plants, as shown for example in U.S. Pat. No. 3,413,784, Jezek, COTTON STRIPPING APPARATUS, issued Dec. 3, 1968. Further examples of this type of apparatus are provided by U.S. Pat. No. 3,757,502, Hubbard, COTTON HARVESTER, issued Sept. 11, 1973 and assigned to the assignee of this application, and U.S. Pat. No. 3,509,700, Jezek, COTTON STRIPPING APPARATUS, issued May 5, 1970.
The above examples of crop harvesting equipment employ a variety of different arrangements for adjusting the height of the harvesting heads relative to the ground. In the case of cotton pickers having rotatable cylindrical picking apparatus, vertical adjustment of each cylinder or drum can typically be made without regard for height adjustments of one side of the drum relative to the other because of the relatively small lateral dimensions of the drum. In those arrangements where cotton stripping fingers are employed, the commonly mounted fingers are typically provided with a single height adjustment achieving a desired nominal or average height of the fingers. However, as such arrangements are made larger, particularly in the transverse direction, and as increasing demands are placed on such equipment for speed and accuracy, a single height adjustment is often found to be inadequate. For example, a single height adjustment fails to compensate for variations in terrain which may place one end of the stripper fingers at approximately the desired height above the ground while the other end of the stripper fingers is at a different and unwanted height.
One approach to the problem of providing relative variations in the height of opposite ends of relatively large crop harvesting equipment is shown in U.S. Pat. No. 3,981,125 to Kerber et al entitled LEVELING MECHANISM FOR HARVESTER HEADERS, issued Sept. 21, 1976. In Kerber et al a mechanism causes a supporting feeder housing to distort, providing a side-to-side rocking motion of an attached harvester platform. The resulting pivoting motion of the harvester platform about a longitudinal axis provides for relative variations in the heights of the opposite ends of the platforms. The difficulty with such an arrangement lies in the fact that the arrangement itself is nothing more than a pivoting arrangement and does not perform actual height adjustment as such. For example, it is impossible to maintain one end of the platform at a fixed desired height while varying the other end of the platform since adjustment of the platform angle necessitates changes in the heights of both ends. A further limitation resides in the fact that the procedure involved in changing the angle of the platform is a relatively involved and time consuming one which does not lend itself to frequent adjustments in the relative heights of the various portions to the harvester platform as varying terrain is encountered.
Accordingly, it is an object of the present invention to provide crop harvesting equipment having improved height adjusting arrangements in accordance with the invention.
A further object of the invention is to provide crop harvesting equipment in which the opposite ends of a harvesting head are adjustable in height independent of one another so as to position each of the opposite ends of the head at desired heights above the ground.
A still further object of the invention is the provision of a cotton stripper in which the opposite ends of a generally planar array of parallel, spaced-apart stripping fingers are individually and independently adjustable to a desired height.